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. e. DOLNE-DEHANf V ALVELESS TWO-STROKE ENGINE. A PPLICAHON .HLED NOV. 22, I912. RENEWED NOV. 6,1918.

1 ,30636 1 Patented J 11110510, 1919.

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n Specification of Lettersfl 'atentaf Patented Jane '10, n

" a ncatitamea l qoiremher 22, 19 12; Serial m,*ii-aj,aeo. Renewed Novemher 6'; 191a. serial-n6. 261,415,

I To-all'whom it jmay 'concem:

Be it known that I GAST N Donna-Damn, a subject'of theKin'gof Belgium, residing Gointe, Selessin, near" Liege, Belgium, have invented certain new and usefulImprove ments in Valiz'eless Two-Stroke Engines and .I {do hereby declare thefollowing tobe a 1 full, clear; and exact description of the, i11- vention, such as-will enable others skilled in i companying drawings, and to letters or fi tires of reference marked the1-ein,gwhi5i form apart of thisspecification'.

I .tion i's'fi'ectedby in'ean's' o'f an engine piston- The presentinyention relates to a va'lyeless two-strokeiengine in which the' distribu-' upon" which is mounted an'.- extension or trol by which extreme precision and rapidity V a I also the path of the gas is reduced as much as possible between" its entry'and the ex haust'i 'Mearrs are also employed for pre enting thejformation of eddies 'inthe en ginebylincler duri'ng the scavenging of the burned gases by freslrgases. 1

In th drawings'annexed'jto the specification and'forming part thereof three embodiments ofthe' invention are illustrated:

Figures 1 and 2 are sections through the Y axis of theengi-ne cylinder showing two dif- A er Fig.1;

the carbureter; before their access to the in- 'ferent positions of the distributing inecha nismfin an engine in which the crankcase serves as the'body of the pump. 'Fi 3 -is horizontalsection on the line 4 represents the throttlin rneniber,

Fig, 5 is a section similar to that shown in Fig. 1 of an engine in' which'thepulnp is .se arate from. the crank case.

I 1g. 6 1s a section similar to that shown in Fig. 1, in an engine in which the gases from the art to'which-it' 'appert'ains to make and use the same, reference being had to the ac- 1 speeds.

let ports, pass through an an'nular chamber-1 which is arr g d et een the; inlet andthe escape.

' F1g. 71is a-section the line v The piston when, rising maths; eflinder creates beneath it comparatively a vacuum until the moment in which the ports 5 are uncovered by the loweredge of-the piston.

llherefor f-resh gas'co'nducted by a circular pipe is drawn into the body o't'the pump. The arrangement of the openings 5 any de-' sired nufiiberofwhiCh maybe used opposite one'another results in a thorough mixing of v the fresh gas in the-pump and "producesa 'h'oniogeneousafluid.

Upon the descent of the piston the gas thus introduced-into the pump and shut up therein when the ports v5 are closed is tension of the piston coincide with the passages 7' formed in the Walls of the cylinder. The ;s'pecial shape' of the passages 7 ,as' well as the conical'form of the base ofthe piston which latter has radialpartition-s forming piston channels enlarging toward the top of the cylinder and forming a continuation of the line of thepassagesB all together give u number of indispensable conditions which bring about the Stratification of fresh gas and burned gas in the cylindeix; Intact, the passages 7 which are indepemlent .fl'oln one another and which are made'jot rather an slightly compressed until the'ino'inent when the passa es 3 formed in the base of the ex elongated shape break up the eddies caused.

byt hepassage otthe gas intothe pump andv prevent these eddies from being transmitted into the' engine cylinder. The quite smooth curve which joins these passages to the passages 3 gives the gas the slightly convergent course'required but without allowing it to turnback, which latter is a fruitful causeot eddiesand whirls, nioreparticularly at high The direction of the passagcs. 3 and the sages and the gas therefore passes from the this method of operation does not give ef-' pump to the cylinder without having eddies or gyratory motions set up in it.

The burned gases from the preceding explosion'after being exhausted quickly are caused to pass out by the sudden opening of the circular passage 6 and are -completely expelled by the scavenging of the fresh gas and this takes place without any appreciable mixing with the latter owing to the manner in which the gas is supplied by the passages 7 and 3 and avoiding all disturbance. The extension of the piston 1 uncovers the exhaust. ports at its upper edge 4 and the portsuncovered occupy the whole of the circumference of the cylinder. Owing'to this the opening is sudden and rapidly presents a considerable area for a small movement of the piston.

This arrangement results in an exhaust which is both rapid and regular producing a quick and extremely vigorous expansion which causes as is known the formation of a quite appreciable vacuum in the cylinder.

In order to prevent'the fresh gases mixing with the burned gases eddies must be prevented both upon theexhaust from and the supply to the engine cylinder. This is what is effected by the arrangement described. The method of controlling this engine is shown in detail in the sections of Figs. 3

and 4 and is based upon the following considerations.

In two-stroke engines commonly used the power of the engine is regulated by acting upon a butterfly throttle valve and the level of the gas in the carbureter as in fourstroke engines, in fact, such a method is employed to control directlythe supply to the pump in the same manner as it affects the supply to the engine cylinder in fourstroke engines. Now it is to be noticed that fective results and flexibilityv in two-stroke engines to the same extent as in four-stroke engines.

In some engines it has been'attempted toeffect the carburation after the-gases have passed through the pump, viz. in the cylinder, but this always causes thecreation of" eddies which is troublesome. It is more simple to carryout the throttling not between the carbureter and'the pump but be tween the pump and the cylinder, this allows an excellent mixing to take place in the pump; From another point of view it is necessary that the throttle shall not interfere with the operating functions of the engine so'that we have not interfered with the part played by the passages 7 and 3 by Without going in detail into the complex phenomena'which accompany these placing at the bottom of the cylindera throttle member 8 shownin (Figs. and 2) and in detail in Fig. 4.

Any controlling arrangement whatever, for example, an endless screw, a rack or the like enables this member to be rotated through such an angle that the notches in it may coincide more or less with the openings of the passages 7'. The directing effect of these passages is not disturbed by this member and the function of this throttle is performed by the engine cylinder. Further,

' the pump remaining filled with mixture con;

tains a reserve of perfectly homogeneous gas, which can instantaneously comply with the needsof a sudden load and the presence of the pump aflords an additional regulating effect in the system by causing the carbureter to act more gently; In other words it acts the part of a damper.

The system can be applied to an 'engine with an independent pump aslwell'asto an engine whichcompresses in the crank case or to a similar construction. As the cylinders are quite independent they may be grouped in an even numberor an odd numder as is shown in Fig. 5 and are therefore i continually in communication with n the source of gas. The suppression of the admission ports to the crank case leaves more space for the passages, the number of the latter can therefore be multiplied around.

the cylinder and this gives more regularity still to the flow of air. v

The carburation can naturally take place 7 either beforeor after passing through the pump a nd mfay take place even in the cylinder itself; this system fasfdescribed *may be applied to all kinds of internal combustion engmes:

Fig. 6 shows an example of engine in which that portion of the engine cylinder which is comprised between the escape and the inlet is'cooled by means of the carbureted gases. Only that portion of the engine cylinder which is arranged above the escape is cooled .by means of water. I

The circular pipe which conducts the gas to the inlet openings into the crank case extends upward and forms a chamber 9 by means of the casing 10 exactly as is the case for an ordinary water cooling, but in the present exam le a single aperture 11 com- 7 munlcates wit the exterior and is arranged in a tangential direct on at the top underthe escape 6. x V I The carbureter which communicates directly with the aperture 11 or preferablyv is mounted there()n,-discharges the gas, which iscooled by the evaporating-fuel, in the directlon of" the arrow. Ow ng to the, special arrangement of the inlet openings the gases take up a gyratory. movement which takes itto the admission ports after going through a. spiral path around the cylinder .for cooling the latter.

- andrcturns of gases which occur-in the known engines; the passage of the gases through the carburetor is thus regularized and the inertia, instea'd of causingan injurious effect. (the return-of gaseslcauses .at each ob-turation a compression of the gases into the casing 10. This compression however depending from the suction speed, favors considerably, the-filling ofthe' pump when theengine runsat great velocity.

When the speed decreases thegases eirculate'much slower around the cylinder and remain much longer in contact with said bustion are more'diflicult, but the heating of duit, the latterneedsnot tobe. heated;

' engine in which the whole of'the distidbu cylinder and they thereby absorb aportion of the heat from thefcylinder. Because of" the slo \v'operation of the motor, the gas 15. poorer v11,1 13631510161111 than when running at' normal speed since its ignition and its comignitlon and combustion thereof.

'- If the c'arbureter is mounted on theconthe gases as abovedescribed, facilitates the What I claim .is

L-In a two stroke internal combustion tionis operated by the piston, the' combination of a-cylinder provided'with admission and exhaust ports, said. exhaust ports encircling the whole of thecircumference of said cylinder, a pum barrel, channels copnecting thepump-barrel and cylinder, said admission ports being-disposed above. said channels and a sleeve piston the circular upper edge of which uncovers the exhaust ports at the lower end of the stroke while the lower edge uncovers the admission. ports located peripherically, said opening taking place when the piston is at theupper end ofits stroke.

vi ed with exhaust ports, and having peri- 2. In a .twostroke internal combustion en "ne the combination of a cylinderpropherically located admission ports, a pump barrel, connecting. channels between said pump barrel and cylinder, said admission ports and said connecting channels being 'in' order to vided admission ports, a pump when atthe upper'end of their opening of the admission ports to the pump by the lower edge of the piston, owing-to the alternately arranged, a-sl eeve piston prescntin'g, at the level of itsbottom channels disposed in radiating planes and registering when at the 'lowcrend of the stroke piston with the connecting channels in 'the cylinder, the'piston channels enlarging toof said ward one end, whose enlargements are direc-ted toward the top of the'cylinder, each of the connecting channels in" the cylinder forming a converging curved nozzle, the

narrow end of which registers with the smallest section of a piston channel.

' -3. In a two-stroke internal combustion engine, the. c'ombinationof a pump barrel and a cylinder having connecting channels between them. said channels .being separated-from one. another and constructed in the form .of converging-curved-nozzles; a

notched ,Washer concentric with the cylinder and'located at the lower part of the channels, each of the notches in said washer rcgisteriiig with one of the channels in orderthat a partial revolution of the washer can simultaneously, obturate' more or less all the channels to the same degree.

. 4'. In a two-str he .'nternal combustion engine, the combination of a cylinder provided in its upper part with exhaust ports and having admission ports, a pump barrel. connecting channelsbetween sald pump bar- .rel and cylinder, said channels be ng. shaped as converging nozzles, a sleeve piston the Y upper edges of which uncover completely the exhaust ports and the bottom of which is formed-by thejuxtaposition of a'number of segmental chambers separated by partitions 5.111 a two-stroke internal combustion engine, the combination of a cylinder pro-- in its upper part with exhaust and barrel having conhinder, the gyratory motions-ofthe gases in the axis of the cylinder.

necting channels between .itand-said eyhndensaid admission ports being located peripherically and above the level. at which said. connectmg channels openya sleeve pistonhaving channels adapted to pass between the admission ports without any communication," said sleeve-piston uncovering the exhaust ports by its upper edge and namediately afterwardconnecting the pump barrel with the inside of the cylincl-er, owing to the alinenientof the piston channels and the connecting channels, while permitting, stroke, the

respective position of the admission ports andthe-connecting channels.

6. In a two-stroke, internal combustion enginethe combination of a cylinder provided inits upper part with exhaust ports and having admission ports, a pump barrel having connecting channels between it-andv said cylinder, said cylinder having a circular chan= nel encircling the cylinder and connected gentially to its periphery so that the carbureted fuel may circulate in the same direction of rotation in the oircularchannel and become more or less compressed by their own kinetic energy at every closing of the admission ports by the lower edge of the 10 sleeve piston.

In testimony'that I claim the foregoing as I my invention, I have signed my name in presence of two subscribing witnesses.

' GASTON DOLNE-DEHAN.

I Witnesses:

A. P. CRUGER, CHARLES BECKER.- 

